Interaction between crystal violet and anionic surfactants at silica/water interface using evanescent wave-cavity ring-down absorption spectroscopy

► Anionic surfactant aggregation on the surface and its interaction with crystal violet (CV+) are studied. ► The results of critical hemimicelle concentration (HMC) on the surface are evaluated. ► Phase change for dye-surfactant interactions at concentration below HMC is found. ►Desorption rates of CV+ are measured. ►The consequences help with understanding how to apply surfactants in the chromatographic separation.